Ancient Greek Geeks Got It Right

Oct. 17, 2007

By LEE DYE

Mark Schiefsky has spent years studying ancient Greek manuscripts, trying to figure out how some of the earliest geeks produced mechanical devices that were at least as important to them as computers are to us.

Schiefsky is a professor of classics at Harvard University and an expert on Greek antiquities, and he is puzzled by the fact that as early as the fifth century B.C., the marketplace in Athens had pretty sophisticated devices for weighing merchandise based on the leverage that can result from an uneven balance bar.

He's puzzled, because the theory of levers wasn't developed until Archimedes came onto the scene in the third century B.C., more than 100 years later.

"It seems clear that there were these balances with unequal arms around before Archimedes," said Schiefsky, one of several scholars who are studying ancient Greek manuscripts at the Max Planck Institute for the History of Science in Berlin.

That flies in the face of the way science and technology work today.

First, there is mathematics, the science of dealing with the measurement, properties and relationships of quantities, and then there is theory, a general principle helping to explain and predict natural phenomena. With both of those tools in hand, experimenters can then go forth and develop the tools to do the work.

But the ancient Greeks got it backward. With very little in the way of mathematics, and even less in science theory, they came up with some really clever gizmos.

"When you say balance, everybody thinks you mean something like the scales of justice with two equal arms and the scale pans on each side," Schiefsky said in an interview. "I was surprised to learn that there were also balances with unequal arms."

The balances used by the ancient Greeks looked sort of like an old-fashioned teeter-totter, with the balance point, or fulcrum, located off-center. That allowed them to weigh, or move, a heavy load with a lighter weight.

"How can you move a 100-pound weight with 10 pounds?" Schiefsky asked. "You can do it if you put the 100-pound weight 10 times closer to the fulcrum."

"Or if you have a very heavy piece of meat you want to weigh, you can do it with a fairly small counterweight," Schiefsky said.

The key is to use the fulcrum as a leverage point, something just about everybody understands today. But here's the problem: Some of these devices were built at least a century before Archimedes came along to develop the law of the lever, which should have been the foundation for devices that had already been built.

Not only did the ancients build these things before they presumably knew what they were doing, but they also figured out how to use them to cheat their neighbors. Some of the old texts indicate that there was a little larceny in the marketplace, although it's doubtful that the ancient Greeks invented that all-too-common human trait.

"They could fiddle around with the measurements," Schiefsky said. "You could rig the balance" by shifting the fulcrum ever so slightly, or shaving an ounce off the counterweight, "so you don't give away as much stuff as the person thinks he is getting."

Once they had figured out how to cheat, the obvious progression was from the balance bar to implements of war. Schiefsky said the old manuscripts show that even in those days much of the technological progress came from weapons development, just as it does today. But some of the devices seem to be much more advanced than ancient math and physics could support.

The ancient Greeks had progressed well beyond the bow and arrow, "which has been around sort of forever," Schiefsky said, and they built catapults that could launch huge rocks at enemy fortresses, sort of precursors to cruise missiles.

"They built these boxlike frames that had long arms, which were stuck between twisted fibers of animal sinew, so they could launch very heavy rocks. This probably happened sometime in the fourth century B.C," he said.

By the next century, Archimedes was on the scene, and theories about proportions and leverage and so forth gave the old Greeks the tools they needed to refine their catapults, making them small enough to be moved, but big enough to get the job done. It's hard to do that kind of thing without math.

Schiefsky thinks those early craftsmen relied a little on trial and error, but it probably went beyond that. He got into studying mechanics because of his interest in the early history of medicine. Systematic testing of various herbs and remedies appear in some of the very early texts, suggesting that early practitioners had developed a crude form of clinical trials.

"You observe what works in one case and not in another, and gradually you build up a base of experience," and that's probably what helped the ancient Greeks develop some of their tools, Schiefsky said.

You don't have to understand the laws of thermodynamics to know that if you stick your hand in the fire you're going to get burned. But if you want to build a better stove, understanding such theories as heat conductivity would raise the ceiling considerable.

Archimedes provided a platform on which early workers could stand, and it was good enough to inspire technological innovation for many centuries. He remains one of the giants of early science, but even Archimedes stretched a point or two.

As the "inventor" of leverage, he claimed that if he had somewhere else to stand, he could move Earth.

It would take a very long pole, and a very strong pole, and my guess is he couldn't have done it. There is this stuff called inertia.

Archimedes' point, Schiefsky said, may have been a slight exaggeration, but "if you have a fixed resting point, and you have a fulcrum and you have a lever that's long enough and strong enough, in principle it's possible, even if it is a little bit of an exaggeration. It conveys the recognition of an exact proportionality. The lever is the main discovery of ancient theoretical mechanics."

After Archimedes, it took a couple of thousand years for Isaac Newton to come along and fill in a lot of gaps.

Lee Dye is a former science writer for the Los Angeles Times. He now lives in Juneau, Alaska.

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